Intake air heater for an air-compressing injection internal combustion engine

ABSTRACT

A suction air heater for an air-compressing injection-type internal combustion engine which includes a spark plug and fuel injection nozzle arranged in an air suction pipe and an electric motor driving a fuel pump; an oil pressure switch controlling the operation of the heater is provided in the internal combustion engine which assures that energy is supplied to the electric motor when the engine is running; a temperature-dependent switch is series-connected with the oil pressure switch for selectively opening or closing the circuit of the electric motor while a starter switch may be connected in parallel with the oil pressure switch.

Tlnited States Patent T ranlrle [4 Apr. 18, 1972 [54] INTAKE AIR HEATERFOR AN AIR- 56 References Cited ION INTERNAL UNITED STATES PATENTS3,020,903 2/1962 Kloss ..l23/l79 H X 1 lnvenwrr Gerhard Frankie,Grunbach Krels 3,024,777 3/1962 Baker ..123/122 0 Waiblingen, GermanyPrimary Examiner-A1 Lawrence Smith [73] Assgnee' 323 f;ffigf gg'figfiAttorney-Craig,Antone11i& Hill [22] Filed: Oct. 28, 1970 [57] ABSTRACT[2 A N 84,633 A suction air heater for an air-compressing injection-typeinternal combustion engine which includes a spark plug and fuelinjection nozzle arranged in an air suction pipe and an electric 1Foreign Application Priority Dam motor driving a fuel pump; an oilpressure switch controlling Oct 29 1969 Germany P 19 54 497 9 theoperation of the heater is provided in the internal combustion enginewhich assures that energy is supplied to the electric motor when theengine is running; a temperature-de- [52] Cl "123/179 23/198 pendentswitch is series-connected with the oil pressure switch for selectivelyopening or closing the circuit of the electric [5 l 1 g Z g motor whilea starter switch may be connected in parallel with 123/198 D, 198 DB theoil pressure switch.

9 Claims, 1 Drawing Figure I IGNITION LOCK or INTERNAL COMBUSTION ENGINEPRESSURE SWITCH 7 +5 ELECTRIC MOTOR STARTER SWITCH TEMPERATURE-RESPONSIVE TRANSMITTER 6 FUEL FEED PUMP PATENTEUAPRIBIHYZ I I 3,656,465

| l I E I IGNITION LOCK 0F INTERNAL COMBUSTION ENGINE WFRESSURE SWITCH 7STARTER 5 SWITCH TEMPERATURE-RESPONSIVE RANSMITTER 6 FUEL FEED PUMPIHVEHTGFI GERHARD FRANKLF BY mg, I\ ta; 1912;,

ATTORNI YS The present invention relates to an intake air heater foraircompressing injection internal combustion engine, essentiallyconsisting of a fuel injection no'ule and spark plug arranged in anintake or suction pipe and of a feed pump driven by an electric motor.

In internal combustion engines operating according to the dieselprocess, intake air heaters have become known for the improvement of thestarting behavior, in which the fuel is combusted in the air intake orsuction pipe of the internal combustion engine in order to increase theintake air temperature.

The intake or suction air heater thereby not only serves as startingassist of internal combustion engines, but it may always be turned on inconjunction with multi-fuel engines when the compression end temperatureis too low.

In order to assure a completely satisfactory switching-on of the intakeair heater during the operation of the internal combustion engine, thepresent invention is concerned with the task to provide an installationthat completely and fully satisfies the requirements made thereof.

underlying problem is solved according to the present invention in thatan oil pressure switch controlling the operation of the intake airheater is arranged at the internal combustion engine which ensures thecurrent supply to the electric motor for the feed pump with a runninginternal combustion engine.

In an advantageous construction of the present invention, a transmittercontrolled in dependence on temperature may be arranged in series withthe oil pressure switch which opens or closes the electric circuit tothe electric motor of the fuel pump.

By reason of the present invention the oil pressure switch may bearranged in parallel to the electric starter switch of the internalcombustion engine.

Accordingly, it is an object of the present invention to provide asuction air heater system for an air-compressing internal combustionengine of the injection type which avoids by simple means theaforementioned shortcomings and drawbacks encountered heretofore.

Another object of the present invention resides in a suction air heatersystem for an internal combustion engine of the aforementioned typewhich assures a completely satisfactory switching on and off of thesuction air heater system during the operation of the internalcombustion engine, taken into due consideration the requirements madethereof.

A further object of the present invention resides in an installation ofthe aforementioned type which is simple in construction and reliable inoperation.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing which shows, forpurposes of illustration only, one embodiment in accordance with thepresent invention, and wherein:

The single FIGURE is a schematic control circuit diagram of theinstallation according to the present invention.

Referring now to the drawing, a conventional oil pressure switch 3 isarranged in the control circuit of a suction air heater, shown onlyschematically and of conventional construction between an ignition lock1 and a conventional transmitter 2 controlled in dependence ontemperature. An electric starter switch 4 is connected in parallel tothe oil pressure switch 3. The transmitter 2 is connected with a feed orfuel pump 6 driven by an electric motor 5.

When the ignition lock 1 is turned on, a voltage exists in the starterswitch 4. If the starter switch 4 is now actuated, then the currentcircuit to the electric motor 5 is closed by way of the transmitter 2 sothat the feed pump 6 is set into operation and fuel is supplied to thesuction air heater whereby the fuel is atomized and at the same timeignited there at.

As a result of the starting of the internal combustion engine,

the oil pressure switch 3, which is connected with the oil circulatorysystem of the mtemal combustion engine, IS closed whereby, also aftertermination of the starting operation (with contact 7 open), the suctionair heating system continues to operate for such length of time untilthe transmitter 2 terminates the operation or in case of need permitsthe same to commence anew.

It is simultaneously assured by the oil pressure switch 3 that thesuction air heating system can operate only with a running internalcombustion engine.

While I have shown and described only one embodiment in accordance withthe present invention, itis understood that the same is not limitedthereto, but is susceptible of numerous changes and modifications asknown to those skilled in the art, and I therefore do not wish to belimited to the details shown and described herein, but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

What I claim is:

1. An intake air heater system for an air-compressing injection internalcombustion engine which includes a fuel injection nozzle arranged in asuction air pipe and a spark plug as well as a feed pump driven by anelectric motor, characterized in that an oil pressure switch meansoperable to control the operation of the suction air heater is arrangedat the internal combustion engine and is connected in a control circuitmeans for the electric motor to ensure a current supply to said electricmotor with a running internal combustion engine.

2. An intake air heater according to claim 1, characterized in that saidoil pressure switch means operates in dependence of the pressure in theoil circulatory system of the engine.

3. An intake air heater according to claim 2, characterized in that atransmitter means controlled in dependence on temperature isseries-connected with the oil pressure switch means, said transmittermeans being operable to selectively open or close the control circuitmeans to the electric motor.

4. An intake air heater according to claim 3, characterized in that theoil pressure switch means is connected in parallel to an electricstarter switch means of the internal combustion engine.

5. An intake air heater according to claim 1, characterized in that atransmitter means controlled in dependence on temperature isseries-connected with the oil pressure switch means, said transmittermeans being operable to selectively open or close the control circuitmeans to the electric motor.

6. An intake air heater according to claim 1, characterized in that theoil pressure switch means is connected in parallel to an electricstarter switch means of the internal combustion engme.

7. An intake air heating system for an air-compressing internalcombustion engine with fuel injection, which includes a fuel pump for aninjection nozzle arranged in an air suction pipe of the engine, sparkplug means for igniting the injected fuel and a control circuit for anelectric motor drivingly connected with the fuel pump, characterized inthat the control circuit includes an oil pressure switch means operableto close the circuit and thus provide electrical energy for the electricmotor in the presence of a predetermined pressure in the oil circulatorysystem of the engine.

8. A system according to claim 7, characterized in that said circuitincludes, connected in series, a switch operated by an ignition lock,said oil pressure switch means and a further switch means selectivelyopened or closed in dependence on temperature.

9. A system according to claim 8, characterized in that a switchactuated by a starter means is connected in parallel with the oilpressure switch means.

1. An intake air heater system for an air-compressing injection internal combustion engine which includes a fuel injection nozzle arranged in a suction air pipe and a spark plug as well as a feed pump driven by an electric motor, characterized in that an oil pressure switch means operable to control the operation of the suction air heater is arranged at the internal combustion engine and is connected in a control circuit means for the electric motor to ensure a current supply to said electric motor with a running internal combustion engine.
 2. An intake air heater according to claim 1, characterized in that said oil pressure switch means operates in dependence of the pressure in the oil circulatory system of the engine.
 3. An intake air heater according to claim 2, characterized in that a transmitter means controlled in dependence on temperature is series-connected with the oil pressure switch means, said transmitter means being operable to selectively open or close the control circuit means to the electric motor.
 4. An intake air heater according to claim 3, characterized in that the oil pressure switch means is connected in parallel to an electric starter switch means of the internal combustion engine.
 5. An intake air heater according to claim 1, characterized in that a transmitter means controlled in dependence on temperature is series-connected with the oil pressure switch means, said transmitter means being operable to selectively open or close the control circuit means to the electric motor.
 6. An intake air heater according to claim 1, characterized in that the oil pressure switch means is connected in parallel to an electric starter switch means of the internal combustion engine.
 7. An intake air heating system for an air-compressing internal combustion engine with fuel injection, which includes a fuel pump for an Injection nozzle arranged in an air suction pipe of the engine, spark plug means for igniting the injected fuel and a control circuit for an electric motor drivingly connected with the fuel pump, characterized in that the control circuit includes an oil pressure switch means operable to close the circuit and thus provide electrical energy for the electric motor in the presence of a predetermined pressure in the oil circulatory system of the engine.
 8. A system according to claim 7, characterized in that said circuit includes, connected in series, a switch operated by an ignition lock, said oil pressure switch means and a further switch means selectively opened or closed in dependence on temperature.
 9. A system according to claim 8, characterized in that a switch actuated by a starter means is connected in parallel with the oil pressure switch means. 